Frequency division multiple access (FDMA) support for wakeup radio (WUR) operation

ABSTRACT

An access point establishes a first communication channel as a primary channel of the access point, and transmits wakeup radio (WUR) beacon frames via a second communication channel, different than the first communication channel, that corresponds to a WUR primary channel. The access point negotiates, with a client station, a third communication channel, different than the first and second communication channels, via which the access point is to transmit wakeup frames for the client station. The access point generates a wakeup frame for transmission to the client station via the third communication channel, generates a wakeup packet to include at least the wakeup frame, and transmits the wakeup packet, including transmitting the wakeup frame to the client station via the third communication channel.

CROSS REFERENCES TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/406,894, now U.S. Pat. No. 10,873,909, entitled “Frequency DivisionMultiple Access (FDMA) Support for Wakeup Radio (WUR) Operation,” filedon May 8, 2019, which claims the benefit of U.S. Provisional PatentApplication No. 62/668,697, entitled “Frequency Division Multiple Access(FDMA) Support with Wake-Up (WUR) Radio,” filed on May 8, 2018. Bothapplications identified above are hereby expressly incorporated hereinby reference in their entireties.

FIELD OF TECHNOLOGY

The present disclosure relates generally to wireless communicationsystems, and more particularly to wireless communication systemsutilizing low power wakeup radios to implement power saving features.

BACKGROUND

Wireless local area networks (WLANs) have evolved rapidly over the pastdecade, and development of WLAN standards such as the Institute forElectrical and Electronics Engineers (IEEE) 802.11 Standard family hasimproved single-user peak data throughput. For example, the IEEE 802.11bStandard specifies a single-user peak throughput of 11 megabits persecond (Mbps), the IEEE 802.11a and 802.11g Standards specify asingle-user peak throughput of 54 Mbps, the IEEE 802.11n Standardspecifies a single-user peak throughput of 600 Mbps, and the IEEE802.11ac Standard specifies a single-user peak throughput in thegigabits per second (Gbps) range. Future standards promise to provideeven greater throughput, such as throughputs in the tens of Gbps range.

Some WLANs include low cost wireless devices, such as wireless sensors,that do not require high data rates. To reduce operating costs, it isoften useful for such wireless devices to be battery operated orotherwise power constrained. Power saving techniques for reducing powerconsumption are used with such power-constrained wireless devices. Forexample, a WLAN network interface of a power-constrained wireless deviceis put into to a low power state (e.g., a sleep state) for periods oftime in order to decrease power consumption of the wireless device. Whenthe wireless device is ready to transmit data to an access point, theWLAN network interface is transitioned to an active state so that thedata can be transmitted. After the WLAN network interface transmits thedata, the WLAN network interface transitions back to the low powerstate.

A WLAN network interface of a power-constrained wireless device may“wake up” periodically to listen for transmissions from the access pointto determine whether the access point has data to transmit to thewireless device. However, such periodic “wake ups” by the WLAN networkinterface consume power even when the access point has no data totransmit to the wireless device. Therefore, to further reduce powerconsumption, some wireless devices employ a low power wake up radio(LP-WUR) that consumes much less power as compared to the WLAN networkinterface. For example, the LP-WUR does not include any transmittercircuitry and is capable of only receiving very low data ratetransmissions. When the access point is ready to transmit data to thewireless device, the access point transmits a wakeup packet addressed tothe wireless device. In response to receiving the wakeup packet anddetermining that the wakeup packet is addressed to the wireless device,the LP-WUR wakes up the WLAN network interface so that the WLAN networkinterface is ready to receive data from the access point.

SUMMARY

In an embodiment, a method for wireless communications includes:establishing, by an access point, a first communication channel as aprimary channel of the access point; transmitting, by the access point,wakeup radio (WUR) beacon frames via a second communication channel thatcorresponds to a WUR primary channel, wherein the second communicationchannel is different than the first communication channel; negotiatingwith a first client station, at the access point, a third communicationchannel via which the access point is to transmit wakeup frames for thefirst client station, the third communication channel being differentthan the second communication channel; generating, at the access point,a first wakeup frame for transmission to the first client station viathe third communication channel; generating, at the access point, awakeup packet to include at least the first wakeup frame; andtransmitting, by the access point, the wakeup packet, includingtransmitting the first wakeup frame to the first client station via thethird communication channel.

In another embodiment, a communication device comprises a wirelessnetwork interface device associated with an access point. The wirelessnetwork interface device includes one or more integrated circuit (IC)devices configured to: establish a first communication channel as aprimary channel of the access point; control the wireless networkinterface device to transmit WUR beacon frames via a secondcommunication channel that corresponds to a WUR primary channel, whereinthe second communication channel is different than the firstcommunication channel; negotiate, with a first client station, a thirdcommunication channel via which the access point is to transmit wakeupframes for the first client station, the third communication channelbeing different than the second communication channel; generate a firstwakeup frame for transmission to the first client station via the thirdcommunication channel; generate a wakeup packet to include at least thefirst wakeup frame; and control the wireless network interface device totransmit the wakeup packet, including transmitting the first wakeupframe to the first client station via the third communication channel.

In yet another embodiment, a method for wireless communicationsincludes: determining, at a client station, that a first communicationchannel is a primary channel of an access point; tuning a wakeup radioof the client station to a second communication channel that correspondsto a WUR primary channel of the access point when the access point is totransmit WUR beacon frames, wherein the second communication channel isdifferent than the first communication channel; receiving, at the clientstation, WUR beacon frames via the second communication channel;negotiating with the access point, at the client station, a thirdcommunication channel via which the client station is to receive wakeupframes for the client station, the third communication channel beingdifferent than the second communication channel; tuning the wakeup radioof the client station to the third communication channel to receivewakeup frames; receiving, at the client station, a first wakeup framevia the third communication channel; in response to receiving the firstwakeup frame, transitioning a wireless network interface of the clientstation to an active state; and after transitioning the wireless networkinterface of the client station to the active state, transmitting, bywireless network interface of the client station, a packet via the firstcommunication channel.

In still another embodiment, a communication device comprises: one ormore IC devices, and a wireless network interface device associated witha client station. The wireless network interface device is implementedon the one or more IC devices and is configured to: determine that afirst communication channel is a primary channel of an access point; andnegotiate, with the access point, a second communication channel viawhich the client station is to receive wakeup frames for the clientstation. The communication device also comprises a wakeup radio coupledto the wireless network interface device. The wakeup radio isimplemented on the one or more IC devices and is configured to: tune toa third communication channel that corresponds to a WUR primary channelof the access point when the access point is to transmit WUR beaconframes, wherein the second communication channel is different than thefirst communication channel; receive WUR beacon frames via the thirdcommunication channel; tune the wakeup radio to the second communicationchannel to receive wakeup frames; receive a first wakeup frame via thesecond communication channel; and in response to receiving the firstwakeup frame, prompt the wireless network interface to transition to anactive state. The wireless network interface device is furtherconfigured to, after transitioning to the active state, transmit apacket via the first communication channel.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a block diagram of an example wireless local area network(WLAN) having a client station with a low power wake up radio (LP-WUR),according to an embodiment.

FIG. 1B is a block diagram of an example wireless network interfacedevice of an access point included in the WLAN of FIG. 1A, according toan embodiment.

FIG. 1C is a block diagram of an example wireless network interfacedevice of the client station included in the WLAN of FIG. 1A, accordingto an embodiment.

FIG. 1D is a block diagram of an example LP-WUR in the WLAN of FIG. 1A,according to an embodiment.

FIG. 2 is a block diagram of an example wakeup packet, according to anembodiment.

FIG. 3 is a block diagram of an example wakeup packet, according toanother embodiment.

FIG. 4 is a diagram of an example transmission sequence of sequentiallytransmitted wakeup packets, according to an embodiment.

FIG. 5 is a diagram of an example transmission of a frequency divisionmultiple access (FDMA) wakeup packet, according to an embodiment.

FIG. 6 is a block diagram of a transmission exchange between an accesspoint (AP) and a client station, according to an embodiment

FIG. 7 is a flow diagram of an example method for generating wakeuppackets, according to an embodiment.

DETAILED DESCRIPTION

Low power wakeup techniques described below are discussed in the contextof wireless local area networks (WLANs) that utilize protocols the sameas or similar to protocols defined by the 802.11 Standard from theInstitute of Electrical and Electronics Engineers (IEEE) merely forexplanatory purposes. In other embodiments, however, the same or similarpower saving techniques are utilized in other types of wirelesscommunication systems such as personal area networks (PANs), mobilecommunication networks such as cellular networks, metropolitan areanetworks (MANs), satellite communication networks, etc.

In an embodiment, a first communication device (e.g., an AP) isconfigured to negotiate respective wakeup radio operating channels withone or more second communication devices (e.g., one or more clientstations), the respective wakeup radio operating channels occupyingrespective different frequency portions of an operating channel of thefirst communication device. The first communication device is configuredto use the respective wakeup radio operating channels negotiated withthe one or more second communication device to transmit wakeup requestpackets to the corresponding ones of the one or more secondcommunication devices. For example, the first communication devicesimultaneously transmits respective wakeup requests to multiple secondcommunication devices in the respective wakeup radio operating channelsnegotiated with the respective second communication devices. Negotiatingrespective wakeup radio operating channels, and utilizing the respectivenegotiated wakeup radio operating channel to transmit respective wakeuppackets to the plurality of second communication devices, allows thefirst communication to more efficiently utilize its operating channelfor wakeup radio operations as compared to systems that, for example,utilize a single wakeup radio operating channel to transmit respectivewakeup packets to a plurality of second communication devices, in atleast some embodiments.

FIG. 1A is a block diagram of an example WLAN 110, according to anembodiment. The WLAN 110 includes an access point (AP) 114 thatcomprises a host processor 118 coupled to a wireless network interfacedevice 122. The wireless network interface device 122 is coupled to aplurality of antennas 126. Although three antennas 126 are illustratedin FIG. 1A, the AP 114 includes other suitable numbers (e.g., 1, 2, 4,5, etc.) of antennas 126 in other embodiments. As will be described inmore detail below, the wireless network interface device 122 isconfigured to generate and transmit a wakeup packet that can be decodedby low power wake up radios (LP-WURs) in the WLAN 110.

The host processor 118 is configured to executed machine readableinstructions stored in a memory device (not shown), according to anembodiment. The host processor 118 is implemented on an integratedcircuit (IC), according to an embodiment. The wireless network interfacedevice 122 is implemented on one or more ICs. The host processor 118 isimplemented on one IC and the wireless network interface device 122 isimplemented on one or more other, different ICs, according to anembodiment. The host processor 118 is implemented on a first IC and thewireless network interface device 122 is implemented on at least thesame first IC and optionally on one or more second ICs, according to anembodiment.

The WLAN 110 also includes one or more client stations 134. Althoughthree client stations 134 are illustrated in FIG. 1A, the WLAN 110includes other suitable numbers (e.g., 1, 2, 4, 5, 6, etc.) of clientstations 134 in various embodiments. The client station 134-1 includes ahost processor 138 coupled to a wireless network interface device 142.The wireless network interface device 142 is coupled to one or moreantennas 146. Although three antennas 146 are illustrated in FIG. 1A,the client station 134-1 includes other suitable numbers (e.g., 1, 2, 4,5, etc.) of antennas 146 in other embodiments.

The wireless network interface device 142 is configured to go into a lowpower state in which the wireless network interface device 142 consumessignificantly less power as compared to an active state of the wirelessnetwork interface device 142. The wireless network interface device 142is capable of wirelessly receiving and transmitting via the one or moreantennas 146 while in the active state. In an embodiment, the wirelessnetwork interface device 142 is incapable of wirelessly receiving andtransmitting via the one or more antennas 146 while in the low powerstate.

The client station 134-1 also includes a LP-WUR 150 coupled to thewireless network interface device 142 and to at least one of theantennas 146. The LP-WUR 150 is configured to use very low power (e.g.,less than 100 microwatts or another suitable amount of power). TheLP-WUR 150 is configured to use significantly less power (e.g., lessthan 20%, less than 10%, less than 5%, less than 2%, less than 1%, etc.)than the wireless network interface device 142 while the wirelessnetwork interface device 142 is in the active state, according to anembodiment.

The LP-WUR 150 is configured to operate over a smaller bandwidth (e.g.,less than 50%, less than 25%, less than 20%, less than 10%) than thebandwidth of an operating channel of the wireless network interfacedevice 142 while the wireless network interface device 142 is in theactive state, in an embodiment. For instance, in an embodiment, theLP-WUR 150 operates over a communication channel that is approximately 4MHz wide (e.g. 4.06 MHz wide) while the wireless network interfacedevice 142, in an active state, operates over a wider communicationchannel that is 20 MHz wide. In an embodiment, the LP-WUR 150 operatesover a communication channel that is centered within the operatingchannel of the wireless network interface device 142. In anotherembodiment, the LP-WUR 150 operates over a communication channeloperates over a communication channel that is different from theoperating channel of the wireless network interface device 142. Inanother embodiment however, the LP-WUR 150 is configured to operate overa bandwidth that is equal or substantially equal to an operatingbandwidth of the wireless network interface device 142 while thewireless network interface device 142 is in the active state. In anembodiment, the wireless network interface device 142, in an activestate, is further configured to operate over a communication channelthat is wider than 20 MHz (e.g., 40 MHz, 80 MHz, 160 MHz, etc.).

The LP-WUR 150 is configured to receive and decode wakeup packetstransmitted by the AP 114 and received via one or more of the antennas146. The LP-WUR 150 is configured to determine whether a received wakeuppacket includes an address (e.g., a media access control (MAC) address,an association identifier (AID), or another suitable network address)corresponding to the client station 134-1, according to an embodiment.The LP-WUR 150 is configured to generate a wakeup signal in response todetermining that a received wakeup packet includes the addresscorresponding to the client station 134-1. An address corresponding tothe client station 134-1 includes one or more of i) a unicast addresscorresponding to the client station 134-1, ii) a multicast addresscorresponding to a group of client stations that includes the clientstation 134-1, and/or iii) a broadcast address that corresponds to allclient stations, in various embodiments.

When the wireless network interface device 142 is in the low power stateand receives the wakeup signal from the LP-WUR 150, the wireless networkinterface device 142 is configured to transition to the active powerstate in response to the wakeup signal, according to an embodiment. Forexample, when the wireless network interface device 142 is in the lowpower state and receives the wakeup signal from the LP-WUR 150, thewireless network interface device 142 responsively transitions to theactive power state to become ready to transmit and/or receive, accordingto an embodiment.

The host processor 138 is configured to execute machine readableinstructions stored in a memory device (not shown), according to anembodiment. The host processor 138 is implemented on an IC, according toan embodiment. The wireless network interface device 142 is implementedon one or more ICs. The host processor 138 is implemented on one IC andthe wireless network interface device 142 is implemented on one or moreother, different ICs, according to an embodiment. The host processor 138is implemented on a first IC and the wireless network interface device142 is implemented on at least the same first IC and optionally on oneor more second ICs, according to an embodiment.

The LP-WUR 150 is implemented on one IC and the wireless networkinterface device 142 is implemented on one or more other, different ICs,according to an embodiment. The LP-WUR 150 is implemented on a first ICand the wireless network interface device 142 is implemented on at leastthe same first IC and optionally on one or more second ICs, according toan embodiment.

In an embodiment, each of the client stations 134-2 and 134-3 has astructure that is the same as or similar to the client station 134-1.For example, one or both of the client stations 134-2 and 134-3 includesa respective LP-WUR, according to an embodiment. As another example, oneor both of the client stations 134-2 and 134-3 does not include aLP-WUR, according to another embodiment. Each of the client stations134-2 and 134-3 has the same or a different number of antennas (e.g., 1,2, 3, 4, 5, etc.). For example, the client station 134-2 and/or theclient station 134-3 each have only two antennas (not shown), accordingto an embodiment.

FIG. 1B is a block diagram of the wireless network interface device 122of the AP 114 of FIG. 1A, according to an embodiment. The wirelessnetwork interface device 122 includes a MAC layer processor 160 coupledto a physical layer (PHY) processor 164. The PHY processor 164 includesa plurality of transceivers 168 coupled to the plurality of antennas126. Although three transceivers 168 and three antennas 126 areillustrated in FIG. 1B, the PHY processor 164 includes other suitablenumbers (e.g., 1, 2, 4, 5, etc.) of transceivers 168 coupled to othersuitable numbers of antennas 126 in other embodiments. In someembodiments, the AP 114 includes a higher number of antennas 126 thantransceivers 168, and the PHY processor 164 is configured to use antennaswitching techniques.

The wireless network interface device 122 is implemented using one ormore ICs configured to operate as discussed below. For example, the MAClayer processor 160 is implemented, at least partially, on a first IC,and the PHY processor 164 may be implemented, at least partially, on asecond IC, in an embodiment. As another example, at least a portion ofthe MAC layer processor 160 and at least a portion of the PHY processor164 are implemented on a single IC, in another embodiment. For instance,the wireless network interface device 122 is implemented using a systemon a chip (SoC), where the SoC includes at least a portion of the MAClayer processor 160 and at least a portion of the PHY processor 164, inan embodiment.

In various embodiments, the MAC layer processor 160 and/or the PHYprocessor 164 of the AP 114 are configured to generate data units, andprocess received data units, that conform to a WLAN communicationprotocol such as a communication protocol conforming to the IEEE 802.11Standard or another suitable wireless communication protocol. Forexample, in an embodiment, the MAC layer processor 160 is configured toimplement MAC layer functions, including MAC layer functions of the WLANcommunication protocol, and the PHY processor 164 is configured toimplement PHY functions, including PHY functions of the WLANcommunication protocol. For instance, the MAC layer processor 160 isconfigured to generate MAC layer data units such as MAC service dataunits (MSDUs), MAC protocol data units (MPDUs), etc., and provide theMAC layer data units to the PHY processor 164, in an embodiment. The PHYprocessor 164 is configured to receive MAC layer data units from the MAClayer processor 160 and encapsulate the MAC layer data units to generatePHY data units such as PHY protocol data units (PPDUs) for transmissionvia the antennas 126, in an embodiment. Similarly, the PHY processor 164is configured to receive PHY data units that were received via theantennas 126, and extract MAC layer data units encapsulated within thePHY data units, in an embodiment. In an embodiment, the PHY processor164 provides the extracted MAC layer data units to the MAC layerprocessor 160, which then processes the MAC layer data units.

In connection with generating one or more radio frequency (RF) signalsfor transmission, the PHY processor 164 is configured to process (whichincludes, for example, modulating, filtering, etc.) data correspondingto a PPDU to generate one or more digital baseband signals, and convertthe digital baseband signal(s) to one or more analog baseband signals,according to an embodiment. Additionally, the PHY processor 164 isconfigured to upconvert the one or more analog baseband signals to oneor more RF signals for transmission via the one or more antennas 126.

In connection with receiving one or more RF signals, the PHY processor164 is configured to downconvert the one or more RF signals to one ormore analog baseband signals, and to convert the one or more analogbaseband signals to one or more digital baseband signals. The PHYprocessor 164 is further configured to process (which includes, forexample, demodulating, filtering, etc.) the one or more digital basebandsignals to generate a PPDU.

The PHY processor 164 includes amplifiers (e.g., a low noise amplifier(LNA), a power amplifier, etc.), a radio frequency (RF) downconverterconfigured to downconvert received RF signals to baseband signals, an RFupconverter configured to upconverter baseband signals to RF signals fortransmission, a plurality of filters, one or more analog-to-digitalconverters (ADCs) configured to convert analog baseband signals todigital signals for processing, one or more digital-to-analog converters(DACs) configured to convert digital signals to analog signal, one ormore discrete Fourier transform (DFT) calculators (e.g., a fast Fouriertransform (FFT) calculator) configured to convert time-domain signalsto, one or more inverse discrete Fourier transform (IDFT) calculators(e.g., an inverse fast Fourier transform (IFFT) calculator) configuredto convert constellation symbols to time-domain signals, one or moremodulators configured to modulate signals for transmission, one or moredemodulators configured to demodulate received signals, etc.

The PHY processor 164 is configured to generate one or more RF signalsthat are provided to the one or more antennas 126. The PHY processor 164is also configured to receive one or more RF signals from the one ormore antennas 126.

The MAC processor 160 is configured to control the PHY processor 164 togenerate one or more RF signals by, for example, providing one or moreMAC layer data units (e.g., MPDUs) to the PHY processor 164, andoptionally providing one or more control signals to the PHY processor164, according to some embodiments. In an embodiment, the MAC processor160 includes a processor configured to execute machine readableinstructions stored in a memory device (not shown) such as a RAM, a readROM, a flash memory, etc. In an embodiment, the MAC processor 160includes a hardware state machine.

FIG. 1C is a block diagram of the wireless network interface device 142of the client station 134-1 of FIG. 1A, according to an embodiment. Thewireless network interface device 142 includes a MAC layer processor 172coupled to a PHY processor 174. The PHY processor 174 includes aplurality of transceivers 178 coupled to the one or more antennas 146.Although three transceivers 178 and three antennas 146 are illustratedin FIG. 1C, the PHY processor 174 includes other suitable numbers (e.g.,1, 2, 4, 5, etc.) of transceivers 178 coupled to other suitable numbersof antennas 146 in other embodiments. In some embodiments, the clientstation 134-1 includes a higher number of antennas 146 than transceivers178, and the PHY processor 174 is configured to use antenna switchingtechniques.

The wireless network interface device 142 is implemented using one ormore ICs configured to operate as discussed below. For example, the MAClayer processor 172 is implemented, at least partially, on a first IC,and the PHY processor 174 is implemented, at least partially, on asecond IC, in an embodiment. As another example, at least a portion ofthe MAC layer processor 172 and at least a portion of the PHY processor174 are implemented on a single IC, in another embodiment. For instance,the wireless network interface device 142 is implemented using a systemon a chip (SoC), where the SoC includes at least a portion of the MAClayer processor 172 and at least a portion of the PHY processor 174, inan embodiment.

In various embodiments, the MAC layer processor 172 and the PHYprocessor 174 of the client station 134-1 are configured to generatedata units, and process received data units, that conform to the WLANcommunication protocol such as a communication protocol conforming tothe IEEE 802.11 Standard or another suitable wireless communicationprotocol. For example, in an embodiment, the MAC layer processor 172 isconfigured to implement MAC layer functions, including MAC layerfunctions of the WLAN communication protocol, and the PHY processor 174is configured to implement PHY functions, including PHY functions of theWLAN communication protocol. The MAC layer processor 172 is configuredto generate MAC layer data units such as MSDUs, MPDUs, etc., and providethe MAC layer data units to the PHY processor 174, in an embodiment. ThePHY processor 174 is configured to receive MAC layer data units from theMAC layer processor 172 and encapsulate the MAC layer data units togenerate PHY data units such as PPDUs for transmission via the one ormore antennas 146, in an embodiment. Similarly, the PHY processor 174 isconfigured to receive PHY data units that were received via the one ormore antennas 146, and extract MAC layer data units encapsulated withinthe PHY data units, in an embodiment. In an embodiment, the PHYprocessor 174 provides the extracted MAC layer data units to the MAClayer processor 172, which then processes the MAC layer data units.

As discussed above, the wireless network interface device 142 isconfigured to transition between an active state and a low power state.When the wireless network interface device 142 is in the low power stateand receives the wakeup signal from the LP-WUR 150, the wireless networkinterface device 142 is configured to transition to the active powerstate in response to the wakeup signal, according to an embodiment.

The PHY processor 174 is configured to downconvert one or more RFsignals received via the one or more antennas 146 to one or morebaseband analog signals, and convert the analog baseband signal(s) toone or more digital baseband signals, according to an embodiment. ThePHY processor 174 is further configured to process the one or moredigital baseband signals to demodulate the one or more digital basebandsignals and to generate a PPDU. The PHY processor 174 includesamplifiers (e.g., a low noise amplifier (LNA), a power amplifier, etc.),a radio frequency (RF) downconverter configured to downconvert receivedRF signals to baseband signals, an RF upconverter configured toupconverter baseband signals to RF signals for transmission, a pluralityof filters, one or more analog-to-digital converters (ADCs) configuredto convert analog baseband signals to digital signals for processing,one or more digital-to-analog converters (DACs) configured to convertdigital signals to analog signal, one or more discrete Fourier transform(DFT) calculators (e.g., a fast Fourier transform (FFT) calculator)configured to convert time-domain signals to, one or more inversediscrete Fourier transform (IDFT) calculators (e.g., an inverse fastFourier transform (IFFT) calculator) configured to convert constellationsymbols to time-domain signals, one or more modulators configured tomodulate signals for transmission, one or more demodulators configuredto demodulate received signals, etc.

The PHY processor 174 is configured to generate one or more RF signalsthat are provided to the one or more antennas 146. The PHY processor 174is also configured to receive one or more RF signals from the one ormore antennas 146.

The MAC processor 172 is configured to control the PHY processor 174 togenerate one or more RF signals by, for example, providing one or moreMAC layer data units (e.g., MPDUs) to the PHY processor 174, andoptionally providing one or more control signals to the PHY processor174, according to some embodiments. In an embodiment, the MAC processor172 includes a processor configured to execute machine readableinstructions stored in a memory device (not shown) such as a RAM, a readROM, a flash memory, etc. In an embodiment, the MAC processor 172includes a hardware state machine.

FIG. 1D is a block diagram of the LP-WUR 150 of the client station 134-1of FIG. 1A, according to an embodiment. The LP-WUR 150 includes radiofrequency (RF)/analog front-end circuitry 184 coupled to at least one ofthe antennas 146. The RF/analog front-end circuitry 184 includes one ormore amplifiers (e.g., a low noise amplifier (LNA)), an RFdownconverter, one or more filters, and one or more analog-to-digitalconverters (ADCs). In an embodiment, the RF/analog front-end circuitry184 is configured to downconvert an RF signal to a baseband analogsignal, and convert the analog baseband signal to a digital basebandsignal.

The RF/analog front-end circuitry 184 is coupled to digital basebandcircuitry 188. The digital baseband circuitry 188 is configured toprocess the digital baseband signal to determine whether the digitalbaseband signal corresponds to a wakeup packet. The digital basebandcircuitry 188 includes a demodulator that demodulates data from thedigital baseband signal to generate an information signal correspondingto information included in a wakeup packet.

The digital baseband circuitry 188 is coupled to logic circuitry 192.The logic circuitry 192 is configured to process the information signalto determine whether a wakeup packet includes an address (e.g., a MACaddress, an AID, or another suitable network address) corresponding tothe client station 134-1, according to an embodiment. The logiccircuitry 192 is configured to generate the wakeup signal in response todetermining that a received wakeup packet includes the addresscorresponding to the client station 134-1. The logic circuitry 192 isconfigured to generate the wakeup signal in response to determining thata received wakeup packet includes the address corresponding to theclient station 134-1. In various embodiments and/or scenarios, thenetwork address included in the wakeup packet comprises a unicastaddress, a multicast address, or a broadcast address. For example, abroadcast network address generally corresponds to all client stationshaving an LP-WUR, according to an embodiment. As another example, amulticast network address corresponds to the client station 134-1 if theclient station 134-1 has been assigned to a group of client stations(e.g., by the AP 114) that is associated with the multicast networkaddress, according to an embodiment. As yet another example, a unicastnetwork address is be assigned to the client station 134-1 at time ofmanufacture, assigned by the AP 114 when the client station 134 becomesassociated with the network 110, etc., according to various embodiments.

In an embodiment, the wireless network interface device 122 of the AP114 is configured to operate with an operating channel that includesmultiple component channels, including a primary channel and one or morenon-primary (secondary) channels. In an embodiment, each of thecomponent channels of the operating channel of the wireless networkinterface device 122 spans a respective 20 MHz frequency portion of theoperating channel of the wireless network interface device 122. Forexample, the wireless network interface device 122 is configured tooperate with a 40 MHz operating channel that includes two componentchannels, each component channel spanning a 20 MHz frequency bandwidth,in an embodiment. As another embodiment, the wireless network interfacedevice 122 is configured to operate with an 80 MHz operating channelthat includes four component channels, each component channel spanning a20 MHz frequency bandwidth. In other embodiments, the operating channelof the wireless network interface device 122 of the AP 114 operates withan operating channel that includes other suitable numbers of componentchannels and/or component channels that span other suitable bandwidths.

In various embodiments, an LP-WUR of a client station 134 (e.g., theLP-WUR 150 of the client station 134-1) is configured to operate with awakeup radio (WUR) operating channel that is the same as or differentfrom the operating channel of the wireless network interface device 122of the AP 114. In an embodiment, the AP 114 (e.g., the wireless networkinterface device 122) is configured to negotiate with a client station134 (e.g., the client station 134-1 or the wireless network interfacedevice 142 of the client station 134-1) a wakeup radio operating channelin which the LP-WUR 150 of the client station 134 is to operate. Thewakeup radio operating channel negotiated between the AP 114 and theclient station 134 corresponds to a particular component channel of theoperating channel of the wireless network interface device 122 of the AP114, in an embodiment. For example, the negotiated wakeup radiooperating channel of the client station 134 spans a portion of aparticular component channel of the operating channel of the wirelessnetwork interface device 122 of the AP 114, in an embodiment.

In an embodiment, negotiation of a wakeup radio operating channelbetween the AP 114 and a particular client station 134 (e.g., the clientstation 134-1) includes an exchange of management or action framesbetween the AP 114 and the client station 134-1. For example, thewireless network interface device 122 is configured to receive amanagement or an action frame transmitted by the client station 134-1(e.g., by wireless network interface device 142). The management oraction frame is, for example, a probe or an association request frametransmitted by the client station 134-1 to initiate association with theAP 114, in an embodiment. In another embodiment, the management oraction frame is a request frame (e.g., a “WUR operating channel request”frame) specifically designated for wakeup radio operating channelnegotiations. In an embodiment, the management or action frame includesa wakeup radio operating channel element, which, in turn, includes anindication of a particular wakeup radio operating channel, or aparticular component channel corresponding to the particular wakeupradio operating channel, being requested for wakeup radio operations bythe client station 134-1. In an embodiment, the indication of theparticular component channel being requested by the client station 134-1for wakeup radio operations comprises i) a first field (e.g., a 1-octetfield or another suitable field) that indicates an operating class ofthe component channel and ii) a second field (e.g., a 1-octet field oranother suitable field) that indicates a channel number of the componentchannel. In another embodiment, the particular wakeup radio operatingchannel, or the particular component channel corresponding to theparticular wakeup radio operating channel, being requested by the clientstation 134-1 is indicated in the wakeup radio operating channel elementin another suitable manner.

In an embodiment, upon receiving the management or action frame from theclient station 134-1, the wireless network interface device 122 of theAP 114 transmits a response frame (e.g., an association response frame,a wakeup radio operating channel response frame, or another suitableresponse frame) to the client station 134-1. The response frameindicates that the particular wakeup radio operating channel, or theparticular component channel corresponding to the particular wakeupradio operating channel, is accepted by the AP 114 or, alternatively,includes an indication of a different wakeup radio operating channel, ora different component channel, to be used as the wakeup radio operatingchannel by the client station 134-1, in an embodiment. The clientstation 134-1 (e.g., the wireless network interface device 142) isconfigured to receive the response frame transmitted by the AP 114, andto tune the LP-WUR radio 150 to operate in the particular wakeup radiooperating channel negotiated between the client station 134-1 and the AP114, in accordance with the indication in the response frame receivedfrom the AP 114, in an embodiment. Subsequently, when the wirelessnetwork interface device 142 of the client station 134-1 is operating ina low power state, the LP-WUR 150 operates to receive wakeup packetsfrom the AP 114 in the particular wakeup radio operating channelnegotiated between the client station 134-1 and the AP 114, in anembodiment.

In an embodiment, the wakeup radio operating channel of the LP-WUR 150of the client station 134 is independent of an operating channel of thewireless network interface device 142 of the client station 134 when thewireless network interface device 142 is operating in an active state.For example, the operating channel of the wireless network interfacedevice 142 of the client station 134 spans one or more first componentchannels of the operating channel of the wireless network interfacedevice 122 of the AP 114, and the wakeup radio operating channel of theLP-WUR 150 of the client station 134 operates in a second componentchannel of the wireless network interface device 122 of the AP 114, inan embodiment. The second component channel in which the wakeup radiooperating channel of the LP-WUR 150 of the client station 134 operateswhen the wireless network interface device 142 of the client station 134is in a low power state is not necessarily included in the set of theone or more first operating channels in which the wireless networkinterface device 142 of the client station 134 operates when thewireless network interface device 142 is in an active state, in anembodiment. After transitioning to an active state in response to awakeup packet received by the LP-WUR 150 in the second componentchannel, the wireless network interface device 142 begins operation withthe operating channel that spans the first one or more componentchannels, in an embodiment.

FIG. 2 is a block diagram of a wakeup packet 200 used in the exampleWLAN 110 of FIG. 1, according to an embodiment. The wireless networkinterface device 122 of the AP 114 is configured to generate andtransmit the wakeup packet 200 to prompt one or more client station 134to wake up from a low power state (e.g., to transition from a low powerstate to an active state), according to an embodiment. The wakeup packet200 is a single user (SU) wakeup packet configured to prompt a singleclient station 134 (e.g., the client station 134-1) to wake up from alow power state, in an embodiment. In another embodiment, the wakeuppacket 200 is a multi-user (MU) wakeup packet configured to prompt agroup of multiple client stations 134 (e.g., a group of client stations134 that includes the client station 134-1) to wake up from a low powerstate. The wireless network interface device 122 of the AP 114 isconfigured to transmit the wakeup packet 200 in a particular componentchannel, of the operating channel of the wireless network interfacedevice 122, that includes the wakeup radio operating channel previouslynegotiated between the AP 114 and the client station (or stations) 134,in an embodiment. The LP-WUR 150 of the client station 134-1 isconfigured to receive, detect, and decode the wakeup packet 200 in thewakeup radio operating channel of the LP-WUR 150 that was previouslynegotiated between the AP 114 and the client station 134-1, according toan embodiment. The wireless network interface device 142 of the clientstation 134-1 is also configured to generate and transmit the wakeuppacket 200, e.g., to prompt one or more other client station 134 to wakeup from a low power state, according to another embodiment.

The wakeup packet 200 includes an 802.11 preamble portion 204 and apayload that includes a wakeup frame 208. The 802.11 preamble portion204 enables IEEE 802.11 stations (e.g., wireless communication devicesthat are configured to operate according to the IEEE 802.11 Standard) todetect the wakeup packet 200 and determine a length of the wakeup packet200 for the purpose of reducing transmissions by IEEE 802.11 stationsthat will collide with the wakeup packet 200, according to anembodiment.

The 802.11 preamble portion 204 includes a legacy 802.11 preamble 210,which corresponds to a legacy preamble defined by the IEEE 802.11Standard, according to an embodiment. The legacy 802.11 preamble 210includes a legacy short training field (L-STF) 212, a legacy longtraining field (L-LTF) 216, a legacy signal field (L-SIG) 220. The L-STF212 includes signals designed for packet detection and automatic gaincontrol (AGC) training. The L-LTF 216 includes signals designed forchannel estimation and synchronization. The L-SIG 220 includesinformation regarding the wakeup packet 200, including lengthinformation (e.g., in a length subfield (not shown)) that can be used byIEEE 802.11 stations to determine when the wakeup packet 200 will end.

In other embodiments, the wakeup packet 200 includes a legacy preamble(different than the legacy 802.11 preamble 210) that enables stationsthat conform to a different suitable wireless communication protocol(e.g., other than the IEEE 802.11 Standard) to detect the wakeup packet200 and determine a length of the wakeup packet 200 for the purpose ofreducing transmissions by such stations that will collide with thewakeup packet 200, according to an embodiment.

In an embodiment, the 802.11 preamble portion 204 also includes a spooffield 224 that follows the legacy 802.11 preamble 210. The spoof field224 is configured to cause communication devices operating according tothe IEEE 802.11 Standard to fail detection of the wakeup packet 200 asan 802.11 packet, and to thereby cause the communication devicesoperating according to the IEEE 802.11 Standard to discard the wakeuppacket 200, in an embodiment. The spoof field 224 is modulated usingbinary phase shift keying (BPSK) modulation to cause communicationdevices operating according to the IEEE 802.11 Standard to faildetecting of the wakeup packet 200 as an 802.11 packet, in anembodiment. In other embodiments, the spoof field 224 is modulated usingother suitable modulations.

In an embodiment, the spoof field 224 is a repetition of the L-SIG 220.In an embodiment, the spoof field 224 is identical to at least a portionof the L-LTF 216. In other embodiments, the spoof field 224 includes anyother suitable signal and/or information. In an embodiment, the spooffield 224 does not convey any useful information to recipientcommunication devices. In another embodiment, the spoof field 224 doesconvey useful information to recipient communication devices. Forexample, in an embodiment, wakeup packet data (e.g., which includes anetwork address corresponding to an intended client station or stations)is encoded within/on a set of OFDM symbols that includes the spoof field224 and the wakeup frame 208. In some embodiments, the spoof field 224is omitted from the wakeup packet 200.

The wakeup frame 208 includes a wakeup preamble 228. In an embodiment,the wakeup preamble 228 includes signals that enable LP-WURs such as theLP-WUR 150 to detect the wakeup packet 200 and to synchronize to thewakeup packet 200. The wakeup frame 208 also includes a wakeup packetdata portion 232. In an embodiment, the wakeup packet data portion 232includes an address (e.g., a MAC address, an AID, or another suitablenetwork address) corresponding to a client station (or client stations)to which the wakeup packet 200 is intended. Referring now to FIG. 1D,the digital baseband circuitry 188 is configured to detect the wakeuppacket 200 at least by detecting the wakeup preamble 228, according toan embodiment. The logic circuitry 192 is configured to process thewakeup packet body 232 to determine whether the wakeup packet body 232includes an address (e.g., a MAC address, an AID, or another suitablenetwork address) corresponding to the client station 134-1.

In an embodiment, the legacy 802.11 preamble 210 spans a first frequencybandwidth, and the wakeup preamble 228 and the wakeup packet dataportion 232 span a second frequency bandwidth that is narrower than thefirst frequency bandwidth. For example, the first frequency bandwidth is20 MHz and the second frequency bandwidth is a narrower bandwidth suchas approximately 4 MHz (e.g. 4.06 MHz), or another suitable narrowerbandwidth such as 1 MHz, 2 MHz, 5 MHz, 10 MHz, etc. In an embodiment,the first frequency bandwidth is the bandwidth of the component channelof the operating channel of the AP 114 in which the wakeup packet 200 istransmitted and the second bandwidth is the bandwidth of the WURoperating channel of the client station (or stations) 134 to which thepacket 200 is addressed.

FIG. 3 is a block diagram of a wakeup packet 300 used in the exampleWLAN 110 of FIG. 1, according to another embodiment. The wakeup packet300 is a frequency division multiple access (FDMA) multi-user (MU)wakeup packet, in an embodiment. The wireless network interface device122 of the AP 114 is configured to generate and transmit the wakeuppacket 300, according to an embodiment, to simultaneously promptwireless network interfaces devices 142 of multiple client stations 134to wake up from a low power state (e.g., transition from a low powerstate to an active state). The wakeup packet 300 spans multiplecomponent channels of the operating channel of the wireless networkinterface device 122 of the AP 114, in an embodiment. The wakeup packet300 includes respective wakeup frames addressed to respective clientstations (or groups of client stations 134) transmitted in respectivecomponent channels previously negotiated between the AP 114 and theclient stations 134, in an embodiment.

The wakeup packet 300 includes a preamble 304. The preamble 304corresponds to the preamble 204 of the packet 200 of FIG. 2 duplicatedin each of the multiple component channels spun by the wakeup packet300. The wakeup packet 300 also includes a plurality of wakeup frames308. Each wakeup frame 308 is the same as or similar to the wakeup frame208 of the wakeup packet 200 of FIG. 2, in an embodiment. Each wakeupframe 308 includes a wakeup preamble and a wakeup body portion, in anembodiment. Each wakeup frame 308 include (e.g., in a wakeup packet bodyportion) an address corresponding to one or more client stations 134.Each respective wakeup frame 308 includes (e.g., in a wakeup packet bodyportion) an address corresponding to a respective client station (or agroup of client stations) 134, in an embodiment.

In the illustrated embodiment, the wakeup packet 300 spans fourcomponent channels of the operating channel of the wireless networkinterface device 122 of the AP 114, and the wakeup packet 300 includesfour wakeup frame 308 respectively transmitted in respective ones of thefour component channels of the operating channel of the wireless networkinterface device 122 of the AP 114. In an embodiment, the four wakeupframes 308 include a first wakeup frame 308-1 that includes an addresscorresponding to a first client station 134 (STA1) and is transmitted ina first component channel corresponding to a wakeup radio operatingchannel previously negotiated between the AP 114 and STA1, a secondwakeup frame 308-2 that includes an address corresponding to a secondclient station 134 (STA2) and is transmitted in a second componentchannel corresponding to a wakeup radio operating channel previouslynegotiated between the AP 114 and STA2, a third wakeup frame 308-3 thatincludes an address corresponding to a second client station 134 (STA3)and is transmitted in a third component channel corresponding to awakeup radio operating channel previously negotiated between the AP 114and STA3, a fourth wakeup frame 308-4 that includes an addresscorresponding to a fourth client station 134 (STA4) and is transmittedin a fourth component channel corresponding to a wakeup radio operatingchannel previously negotiated between the AP 114 and STA4. In otherembodiments, the wakeup packet 300 spans a number component channelsdifferent than four component channels and the wakeup packet 300includes a corresponding number of wakeup frames 308 different than fourwakeup frames 308.

In an embodiment, the wireless network interface device 122 isconfigured to encode and modulate the wakeup frames 308 for transmissionin the respective component channels of the operating channel of thewireless network interface device 122. In an embodiment, the wirelessnetwork interface device 122 is configured to encode and modulate thewakeup frames 308 using a same modulation and coding scheme (MCS) tomodulate and encode each of the wakeup frames 308. In anotherembodiment, different MCSs are used to modulate and encode respectiveones of at least some of the wakeup frames 308. For example, LP-WURs ofrespective client stations 134 support different MCSs, and the wirelessnetwork interface device 122 is configured to use respective supportedMCSs to modulate and encode respective wakeup frames 134 fortransmission to the corresponding client stations 134, in an embodiment.

In an embodiment, the wakeup packet 300 includes at least one wakeupframe 308 that is of a shorter length compared to one or more motherwakeup frames 308. For example, the wakeup frame 308-2 for transmissionto STA2 is of a shorter length as compared to the length of the wakeupframes 308-1, 308-3 and 308-4 for transmission to, respectively STA1,STA3 and STA4, in the illustrated embodiment. In an embodiment, theshorter length of the wakeup frame 304-2 is due to the wakeup frame308-2 being encoded and modulated according to a higher MCS (e.g.,higher coding rate and/or higher modulation scheme) supported by theLP-WUR 150 of STA2 as compared to an MCS used to encode and modulate thewakeup frames 308-1, 308-3 and 308-4 supported by the LP-WURs of STA1,STA3 and STA4, in an embodiment. Additionally or alternatively, theshorter length of the wakeup frame 304-2 is due to different amount ofinformation included in the wakeup frame 304-2 as compared to the amountof information included in the wakeup frames 308-1, 308-3 and 308-4. Forexample, the wakeup frames 308-1, 308-3 and 308-4 are standard wakeupframes generated according to a standard format supported by the LP-WURsof STA1, STA3 and STA4, while the wakeup frame 308-2 is a custom wakeupframe generated according to a custom (e.g., proprietary) formatsupported by the LP-WUR of STA 2, in an embodiment. In anotherembodiment, all wakeup frames 308 are of the same lengths.

In an embodiment, the wireless network interface device 122 isconfigured to pad the at least one wakeup frame 308 that is of a shorterlength, for example by appending one or more padding bits or one or moremodulation symbols to the at least one wakeup frame 308, to equalize thelengths of the wakeup frames 308. For example, the wireless networkinterface device 122 generates the shorter wakeup frame 308-2 to includea padding portion 326 to equalize the length of the wakeup frame 308-2with the lengths of the wakeup frames 308-1, 308-3 and 308-4, in theillustrated embodiment. In other embodiments, the shorter wakeup frame308-2 omits the padding portion 326. In this embodiment, the packet 300includes wakeup frames 308 of unequal lengths.

In an embodiment, the AP 114 (e.g., the wireless network interfacedevice 122) and the client stations 134 (e.g., the wireless networkinterface device 142) contend for a communication medium using CCAmechanisms, such as carrier sense multiple access with collisionavoidance (CSMA/CA) mechanism or another suitable channel assessmentmechanism. In an embodiment, the AP 114 and the client stations 154maintain respective network allocation vectors (NAVs) that includetimers for tracking when another communication device has seized controlor “ownership” of a wireless communication medium. For example, when acommunication device (e.g., the AP 114 or a client station 154) receivesa transmitted PHY data unit (e.g., the PHY data unit 200 of FIG. 2 oranother suitable PHY data unit) that conforms to a particularcommunication protocol (e.g., the IEEE 802.11 Standard, a future versionof the IEEE 802.11 Standard, or another suitable communicationprotocol), or at least includes a preamble that conforms to theparticular communication protocol, the communication device examinesduration information included in a header or the preamble of the PHYdata unit, where the duration information indicates a length of timethat another communication device has taken ownership of a communicationmedium. The communication device then uses the duration information inthe PHY data unit to set a NAV timer, and the NAV timer begins todecrement. When a value of the NAV timer is non-zero, this indicatesthat another communication device owns the communication medium and thatthe communication device therefore should generally refrain fromtransmitting. On the other hand, when the value of the NAV timer reacheszero, this indicates that the communication medium is not currentlyowned by another communication device.

In an embodiment, when the NAV is zero, the communication deviceimplements a physical carrier sensing and energy detection procedure inwhich the communication device senses an energy level of the medium fora predetermined length of time, such as a length of time correspondingto a distributed coordination function (DCF) interframe space (DIFS)time period or another suitable time period, in an embodiment. Ifdetected energy in the medium during the predetermined length of timeremains below a threshold, then the communication device invokes abackoff procedure in which the communication device continues to detectenergy level of the medium, to determine whether medium is busy or idle,for an additional deferral time period. In an embodiment, the backoffprocedure includes randomly or pseudorandomly choosing an initial valuefor the backoff timer when the current value of the backoff timer iszero. In an embodiment, the communication device chooses the initialvalue for the backoff timer from a range of initial values [0, CW],where CW is a contention window parameter, where the initial value andCW are in units of slots, and where each slot corresponds to a suitabletime period. For example, the IEEE 802.11 Standard defines slot times of20 microseconds (IEEE 802.11b) and 9 microseconds (IEEE 802.11a, 11n,and 11ac), where different slot times are used for different versions ofthe protocol. In an embodiment, CW is initially set to a minimum valueCWmin. However, after each failed transmission attempt (e.g., failure toreceive an acknowledgment of the transmission), the value of CW isapproximately doubled with an upper bound of CWmax. The parameters CWminand CWmax are also in units of slots.

In an embodiment, while the communication device determines that themedium is idle, the communication device decrements the backoff timer.When the communication device determines that the communication mediumis busy, the communication device pauses the backoff timer and does notresume decrementing the backoff timer until the communication medium issubsequently determined to be idle. In an embodiment, setting thebackoff timer to an initial value chosen randomly or pseudo-randomly(e.g., as described above) ensures that backoff timers of differentcommunication devices in the network tend to reach zero at differenttimes. In an embodiment, when the backoff timer reaches zero, thecommunication device determines that the communication device is free totransmit.

In an embodiment, when a communication device (e.g., the AP 114 or aclient station 154) determines that a primary channel is idle based onCCA/backoff operations performed in the primary channel, thecommunication device also checks one or more non-primary channels todetermine whether the one or more non-primary channels can be utilizedfor transmission along with the primary channel. For example, in anembodiment, the communication device senses an energy levelcorresponding to the one or more non-primary channels for apredetermined length of time, such as a length of time corresponding topoint coordination function (PCF) interframe space (PIFS) time period,immediately preceding expiration of the backoff timer corresponding tothe primary channel. If detected energy level corresponding to one ormore of the non-primary channels is below a threshold, the communicationdevice determines that these one or more of the non-primary channels arealso idle. When the backoff timer reaches zero, the communication devicecan transmit in a composite channel that includes the primary channeland the one or more non-primary channels determined to be idle, in anembodiment, in an embodiment.

In an embodiment, the wireless network interface device 122 of the AP114 is configured to perform CCA/backoff procedures prior totransmission of a wakeup packet, such as the wakeup packet 200 of FIG. 2or the wakeup packet 300 of FIG. 2. In an embodiment, when transmittingthe wakeup packet 200 that includes a single wakeup frame and is to betransmitted in a particular component channel of the operating channelof the wireless network interface device 122 of the AP 114, the AP 114performs backoff procedures CCA/backoff procedures based on theparticular component channel of the operating channel of the wirelessnetwork interface device 122 of the AP 114 (e.g., using the particularcomponent channel as the primary channel for the purpose of CCA/backoffprocedures).

FIG. 4 is a diagram of an example transmission sequence 400 in which theAP 114 sequentially transmits respective wakeup packets, such as SU orMU wakeup packet 200 of FIG. 2, that span respective component channelsof the wireless network interface device 122 of the AP 114, according toan embodiment. In an embodiment, the wireless network interface device122 of the AP 114 performs a CCA/backoff procedure 402-1 based on acomponent channel 404-1 for transmission of a wakeup packet 406-1 to afirst client station 134 (STA1) in the component channel 404-1. When thewireless network interface device 122 determines based on theCCA/backoff procedure 402-1 that the component channel 404-1 is idle,the wireless network interface device 122 transmits the wakeup packet406-1 to STA1 in the component channel 404-1. Subsequently, the wirelessnetwork interface device 122 of the AP 114 switches CCA/backoffoperation to a component channel 404-2 to prepare for transmission of awakeup packet 406-2 to a second client station 134 (STA2) in thecomponent channel 404-2. In an embodiment, switching CCA/backoffoperation to the component channel 404-2 includes resetting a NAV timerto a duration value corresponding to the component channel 404-2. In anembodiment, the wireless network interface device 122 resets the NAVtimer based on a duration indication in a header or preamble of a validPPDU that the wireless network interface device 122 receives in thecomponent channel 404-2 upon switching CCA/backoff operation to thecomponent channel 404-2. In another embodiment, the wireless networkinterface device 122 resets the NAV timer to a predetermined value, suchas a predetermined NAVSYNCDELAY value, upon switching CCA/backoffoperation to the component channel 404-2. In yet another embodiment, thewireless network interface device 122 does not reset the NAV timer uponswitching CCA/backoff operation to the component channel 404-2. Forexample, the wireless network interface device 122 carries over thevalue of the NAV timer from the component channel 404-1 to the componentchannel 404-2, in an embodiment.

Upon switching CCA/backoff operations to the component channel 404-2,the wireless network interface device 122 performs a CCA/backoffprocedure 402-2 based on the component channel 404-2, in an embodiment.When the wireless network interface device 122 determines based on theCCA/backoff procedure 402-2 that the component channel 404-2 is idle,the wireless network interface device 122 transmits the wakeup packet406-2 to STA2 in the component channel 404-2, in an embodiment.

FIG. 5 is a diagram of an example transmission 500 of an FDMA MU wakeuppacket, such as the wakeup packet 300 of FIG. 3, that includesrespective wakeup frames in respective component channels of theoperating channel of the wireless network interface device 122 of the AP114, according to an embodiment. In an embodiment, when attempting totransmit an FDMA MU wakeup packet, such as the wakeup packet 300 of FIG.3, to multiple client stations 134, the wireless network interfacedevice 122 of the AP 114 selects a particular one of the componentchannels in which the wakeup frames are to be transmitted to be used forCCA/backoff operations. The wireless network interface device 122performs a CCA/backoff in the selected particular one of the componentchannels. When the wireless network interface device 122 determinesbased om the CCA/backoff operations performed in the selected particularone of the component channels that the particular one of the componentchannels is idle, the wireless network interface device 122 also theother component channels in which the wakeup frames are to betransmitted to determine whether the other component channels can beutilized for transmission along with the selected particular one of thecomponent channels. If the wireless network interface device 122determines that the other component channels in which the wakeup framesare to be transmitted can be utilized for transmission along with theselected particular one of the component channels, the wireless networkinterface device 122 transmits the wakeup packet including the wakeupframe in the selected particular one of the component channels and thewakeup frames in the other component channels. On the other hand, if thewireless network interface device 122 determines that one or more of theother component channels in which the wakeup frames are to betransmitted cannot be utilized for transmission along with the selectedparticular one of the component channels, the wireless network interfacedevice 122 punctures portions of the wakeup packet corresponding to theone or more of the other component channels that cannot be utilized fortransmission, and transmits the punctured wakeup packet that excludesthe wakeup frames corresponding to the one or more of the othercomponent channels that cannot be utilized for transmission, in anembodiment.

Referring still to FIG. 5, the transmission 500 includes transmission ofthe wakeup packet 300 of FIG. 3 without the portion of the wakeup packet300 that includes the wakeup frame 308-2 to STA2. In an examplescenario, the wakeup packet 300 of FIG. 3 is transmitted without theportion of the wakeup packet 300 that includes the wakeup frame 308-2 toSTA2 because the wireless network interface device 122 does not intendto prompt STA2 to transition to an active state, in an embodiment. Inthis scenario, the wireless network interface device 122 does not selectthe component channel corresponding to the wakeup radio operatingchannel of STA2 as the particular channel to be used for CCA/backoffoperations, and does not attempt to determine that the component channelcorresponding to the wakeup radio operating channel of STA2 can beutilized for transmission along with the particular one of the componentchannels selected for CCA/backoff operations. In another examplescenario, the wireless network interface device 122 determines that thecomponent channel corresponding to the wakeup radio operating channel ofSTA2 cannot be utilized for transmission along with the particular oneof the component channels selected for CCA/backoff operations. In thisscenario, the wireless network interface device 122 punctures theportion of the wakeup packet 300 corresponding to the component channelthat includes the wakeup radio operating channel of STA2 prior totransmission of the wakeup packet 300, in an embodiment. Further, inthis scenario, after transmitting the wakeup packet 300, the wirelessnetwork interface device 122 switches the CCA/backoff operations to thecomponent channel that corresponds to the wakeup radio operating channelof STA2 to again attempt to transmit the wakeup frame 308-2 to STA2, inan embodiment.

In an embodiment, upon transitioning to an active state in response toreceiving a wakeup signal generated by an LP-WUR (e.g., the LP-WUR 150)of a client station 134, a wireless network interface device (e.g., thewireless network interface device 142) of the client station 134attempts a transmission to the AP 114, for example a transmissionsolicited by a wakeup frame received by the LP-WUR 150 from the AP 114.For example, the wireless network interface device 142 initiates aCCA/backoff procedure to attempt the transmission, in an embodiment. Inan embodiment, the wireless network interface device 142 is configuredto purposely delay attempting a transmission immediately after the endof the wakeup frame received from the AP 114 to ensure that thetransmission does not occur until the end of the transmission of theentire wakeup packet that includes the wakeup frame, even if the wakeupframe is of a shorter length than the lengths of the entire wakeuppacket.

In an embodiment, the AP 114 (e.g., the wireless network interfacedevice 122) is configured to announce a delay time period indicating aminimum delay time by which client stations 134 are to delaytransmissions after the end of a wakeup frame received from the AP 114.The delay time period is configured to ensure that transmissions by theclient stations 134 will not be initiated before the end of a wakeuppacket that includes wakeup frames for the client stations 134, even ifa particular wakeup frame is of a shorter length than the length of theentire wakeup packet that includes the packet frame. In an embodiment,the wireless network interface device 122 is configured to include anindication of the delay time period in a management frame or actionframe that conforms to the IEEE 802.11 Standard or other wirelesscommunication protocol according to which the wireless network interfacedevices of the client stations 134 are configured to operate, in anembodiment. For example, the wireless network interface device 122 isconfigured to include an indication of the delay time period in an IEEE802.11 beacon frame, an IEEE 802.11 association response frame, an IEEE802.11 probe response frame or another suitable frame, such as a framespecifically designated for announcement of wakeup radio operationparameters. The wireless network interface device 142 of the clientstation 134 is configured to receive the indication of the delay timeperiod and to delay attempting transmissions by the indicated delay timeperiod after the end of a wakeup frame received from the AP 114, in anembodiment. In another embodiment, the delay time period is apredetermined delay time period to be used by the client stations 134.In this embodiment, the AP 114 does not need to indicate the delay timeperiod to the client stations 134.

FIG. 6 is a block diagram of a transmission exchange 600 between the AP114 and a client station 134, according to an embodiment. The AP 114(e.g., the wireless network interface device 122) generates andtransmits a wakeup packet 602. The wakeup packet 602 corresponds to thewakeup packet 300 of FIG. 3, in an embodiment. The wakeup packet 600includes the wakeup frame 308-2, addressed to STA2, that is of a shorterlength than the other wakeup frames 308. In an embodiment, STA2determines the length of the wakeup frame 308-2 based on a lengthindication in a wakeup preamble of the wakeup frame 308-2. STA2,however, does attempt a transmission to the AP 114 immediately after theend of the wakeup frame 308-2 because such transmission would collidewith the still on-going transmission of the wakeup packet 300. Instead,STA2 delays attempting transmission to the AP 114 by a delay time period604 after the end of the wakeup frame 308-2. After the delay time period604, STA2 performs a CCA/backoff procedure 606, and transmits a PPDU 608to the AP 114 when the channel is determined to be idle and availablebased on the CCA/backoff procedure 606. Transmission of the PPDU 608 issolicited by the wakeup frame 308-2, in an embodiment. Delaying the timeat which the CCA/backoff procedure 606 is initiated by the delay timeperiod 604 after the end of the wakeup frame 308-2 ensures thattransmission of the PPDU 608 will not begin before the end of the wakeuppacket 300, in an embodiment.

In an embodiment, the AP 114 (e.g., the wireless network interfacedevice 122) is configured to periodically transmit wakeup radio beaconframes to allow LP-WURs (e.g., LP-WUR 150) of the client stations 134 tosink with the AP 114. In an embodiment, the wireless network interfacedevice 122 is configured to transmit the beacon frames in FDMA duplicatemode in which a beacon frame is duplicated in each component channel ofthe operating channel of the AP 114. Transmitting the beacon frames inFDMA duplicate mode allows LP-WURs of the client stations 134 to receivethe beacon frames in the negotiated respective component channels inwhich the respective LP-WURs are operating.

In another embodiment, the wireless network interface device 122 isconfigured to transmit the beacon frames in non-duplicate mode in only asingle component channel (e.g., the primary component channel or asecondary component channel) of the operating channel of the AP 114. Inan embodiment, the wireless network interface device 122 is configuredto indicate to the client stations 134 (e.g., to the wireless networkinterfaces 142) the particular component channel used for wakeup radiobeacon transmissions and a schedule (e.g., target beacon transmissiontime (TBTT)) for the wakeup radio beacon transmissions. The wirelessnetwork interface device 122 is configured to include indications of theparticular component channel and/or the schedule (e.g., target beacontransmission time (TBTT)) in a management frame or action frame thatconforms to the IEEE 802.11 Standard or other wireless communicationprotocol according to which the wireless network interface devices ofthe client stations 134 are configured to operate, in an embodiment. Forexample, the wireless network interface device 122 is configured toinclude indications of the particular component channel and/or theschedule (e.g., target beacon transmission time (TBTT)) in an IEEE802.11 beacon frame, an IEEE 802.11 association response frame, an IEEE802.11 probe response frame or another suitable frame, such as a framespecifically designated for announcement of wakeup radio operationparameters. The wireless network interface device 142 of the clientstation 134 is configured to receive indications of the particularcomponent channel and/or the schedule (e.g., target beacon transmissiontime (TBTT)) and to configure the LP-WUR 150 to tune to the particularcomponent channel at the designated times to receive the wakeup radiobeacon frames, in an embodiment.

FIG. 7 is a flow diagram of an example method 700 for generating wakeuppackets, according to an embodiment. In some embodiments, the wirelessnetwork interface device 122 of FIG. 1 is configured to implement themethod 700. The method 700 is described, however, in the context of thewireless network interface device 122 merely for explanatory purposesand, in other embodiments, the method 700 is implemented by anothersuitable device, such as the wireless network interface device 142.

At block 702, the wireless network interface device 122 generates one ormore wakeup frames for transmission to one or more client stations. Forexample, the wireless network interface device 122 generates the wakeupframe 224 of FIG. 2, in an embodiment. As another example, the wirelessnetwork interface device 122 generates the wakeup frames 308 of FIG. 3,in another embodiment. In other embodiments, the wireless networkinterface device 122 generates one or more suitable wakeup framesdifferent from the wakeup frame 224 of FIG. 2 or the wakeup frames 308of FIG. 3.

At block 704, the wireless network interface device 122 generates awakeup packet to include the one or more wakeup frames generated atblock 702. For example, in an embodiment, the wireless network interfacedevice 122 generates the wakeup packet 200 of FIG. 2. In anotherembodiment, the wireless network interface device 122 generates thewakeup packet 300 of FIG. 3. In other embodiments, the wireless networkinterface device 122 generates a suitable wakeup packet different fromthe wakeup packet 200 of FIG. 2 or the wakeup packet 300 of FIG. 2. Inan embodiment, the wakeup packet includes the wakeup frames fortransmission in respective ones of one or more particular wakeup radiooperating channels of respective ones of the one or more clientstations. In an embodiment, the respective one or more operatingchannels were previously negotiated between the wireless networkinterface device 122 and respective ones of the one or more secondclient stations.

At block 706, the wireless network interface device 122 transmits thewakeup packet to the one or more client stations, In an embodiment, thewireless network interface device 122 transmits respective ones of theone or more wakeup frames in respective ones of the one or moreparticular wakeup radio operating channels of respective ones of the oneor more client stations. In an embodiment, the wireless networkinterface device 122 transmits the wakeup packet to prompt therespective ones of the one or more client stations to transition from alow power state to an active state. Negotiating wakeup radio channelswith client stations provides flexibility of allowing LP-WURs ofdifferent client stations to operate in different wakeup radio channels,in an embodiment. For example, transmitting the wakeup packet having therespective wakeup frames in respective wakeup radio operating channelsdetermined by previous negotiation with the client stations allows thewireless network interface device 122 to simultaneously prompt multipleclient stations, operating in different wakeup radio operating channels,to transition to active states, in an embodiment.

At least some of the various blocks, operations, and techniquesdescribed above may be implemented utilizing hardware, a processorexecuting firmware instructions, a processor executing softwareinstructions, or any combination thereof. When implemented utilizing aprocessor executing software or firmware instructions, the software orfirmware instructions may be stored in any computer readable memory suchas on a magnetic disk, an optical disk, or other storage medium, in aRAM or ROM or flash memory, processor, hard disk drive, optical diskdrive, tape drive, etc. The software or firmware instructions mayinclude machine readable instructions that, when executed by one or moreprocessors, cause the one or more processors to perform various acts.

When implemented in hardware, the hardware may comprise one or more ofdiscrete components, an integrated circuit, an application-specificintegrated circuit (ASIC), a programmable logic device (PLD), etc.

While the present invention has been described with reference tospecific examples, which are intended to be illustrative only and not tobe limiting of the invention, changes, additions and/or deletions may bemade to the disclosed embodiments without departing from the scope ofthe invention.

What is claimed is:
 1. A method for wireless communications, comprising:establishing, by an access point, a first communication channel as aprimary channel of the access point; transmitting, by the access point,wakeup radio (WUR) beacon frames via a second communication channel thatcorresponds to a WUR primary channel, wherein the second communicationchannel is different than the first communication channel; negotiatingwith a first client station, at the access point, a third communicationchannel via which the access point is to transmit wakeup frames for thefirst client station, the third communication channel being differentthan the second communication channel; generating, at the access point,a first wakeup frame for transmission to the first client station viathe third communication channel; generating, at the access point, awakeup packet to include at least the first wakeup frame; andtransmitting, by the access point, the wakeup packet, includingtransmitting the first wakeup frame to the first client station via thethird communication channel.
 2. The method of claim 1, furthercomprising: switching, at the access point, channel access operations ofthe access point from the first communication channel to the thirdcommunication channel; and performing, by the access point, a backoffprocedure in the third communication channel to determine when the thirdcommunication channel is available for transmission of the first wakeupframe to the first client station.
 3. The method of claim 2, whereinswitching channel access operations of the access point includesresetting a channel access timer to one of i) a duration value obtainedfrom a data unit received by the access point in the third communicationchannel, and ii) a predetermined duration value.
 4. The method of claim1, further comprising: negotiating, at the access point and withmultiple client stations, respective communication channels, within anoperating channel of the access point, via which respective wakeupframes are to be transmitted to the multiple client stations, includingnegotiating, with the first client station, the third communicationchannel via which the access point is to transmit wakeup frames for thefirst client station; and generating, at the access point, multiplewakeup frames that include at least i) the first wakeup frame fortransmission to the first client station, and ii) a second wakeup framefor transmission to a second client station; wherein generating thewakeup packet comprises generating the wakeup packet to include themultiple wakeup frames for transmission in the respective communicationchannels; and wherein transmitting the wakeup packet is in order toprompt the multiple client stations to transition from the low powerstate to the active state, and wherein transmitting the wakeup packetcomprises i) transmitting the first wakeup frame to the first clientstation via the third communication channel and ii) transmitting thesecond wakeup frame to the second client station via a fourthcommunication channel.
 5. The method of claim 4, further comprising: inconnection with transmitting the packet, performing, at the accesspoint, a backoff procedure in the first communication channel todetermine when the access point is permitted to transmit the wakeuppacket; in connection with performing the backoff procedure in the firstcommunication channel, determining, at the access point, whether one ormore communication channels different than the first communicationchannel are idle, wherein the first communication channel and the one ormore communication channels different than the first communicationchannel are within the operating channel; and transmitting, by theaccess point, the wakeup packet in the first communication channel andone or more other communication channels within the operating channelthat are determined to be idle.
 6. The method of claim 5, transmittingthe wakeup packet comprises not transmitting in one or morecommunication channels within the operating channel that are determinedto be busy.
 7. A communication device, comprising: a wireless networkinterface device associated with an access point, the wireless networkinterface device having one or more integrated circuit (IC) devicesconfigured to: establish a first communication channel as a primarychannel of the access point, control the wireless network interfacedevice to transmit wakeup radio (WUR) beacon frames via a secondcommunication channel that corresponds to a WUR primary channel, whereinthe second communication channel is different than the firstcommunication channel, negotiate, with a first client station, a thirdcommunication channel via which the access point is to transmit wakeupframes for the first client station, the third communication channelbeing different than the second communication channel, generate a firstwakeup frame for transmission to the first client station via the thirdcommunication channel, generate a wakeup packet to include at least thefirst wakeup frame, and control the wireless network interface device totransmit the wakeup packet, including transmitting the first wakeupframe to the first client station via the third communication channel.8. The communication device of claim 7, wherein the one or more ICdevices are further configured to: switch channel access operations ofthe access point from the first communication channel to the thirdcommunication channel; and perform a backoff procedure in the thirdcommunication channel to determine when the third communication channelis available for transmission of the first wakeup frame to the firstclient station.
 9. The communication device of claim 8, wherein the oneor more IC devices are further configured to, as part of switchingchannel access operations of the access point: reset a channel accesstimer to one of i) a duration value obtained from a data unit receivedby the access point in the third communication channel, and ii) apredetermined duration value.
 10. The communication device of claim 7,wherein the one or more IC devices are further configured to: negotiate,with multiple client stations, respective communication channels, withinan operating channel of the access point, via which respective wakeupframes are to be transmitted to the multiple client stations, includingnegotiating, with the first client station, the third communicationchannel via which the access point is to transmit wakeup frames for thefirst client station; and generate multiple wakeup frames that includeat least i) the first wakeup frame for transmission to the first clientstation, and ii) a second wakeup frame for transmission to a secondclient station; generate the wakeup packet to include the multiplewakeup frames for transmission in the respective communication channels;and control the wireless network interface device to transmit the wakeuppacket in order to prompt the multiple client stations to transitionfrom the low power state to the active state, and wherein transmittingthe wakeup packet comprises i) transmitting the first wakeup frame tothe first client station via the third communication channel and ii)transmitting the second wakeup frame to the second client station via afourth communication channel.
 11. The communication device of claim 10,wherein the one or more IC devices are further configured to: inconnection with transmitting the wakeup packet, perform a backoffprocedure in the first communication channel to determine when thecommunication device is permitted to transmit the wakeup packet; inconnection with performing the backoff procedure in the firstcommunication channel, determine whether one or more communicationchannels different than the first communication channel are idle,wherein the first communication channel and the one or morecommunication channels different than the first communication channelare within the operating channel; and control the wireless networkinterface device to transmit the wakeup packet in the firstcommunication channel and one or more other communication channelswithin the operating channel that are determined to be idle.
 12. Thecommunication device of claim 11, wherein the one or more IC devices arefurther configured to control the wireless network interface device tonot transmit in one or more communication channels within the operatingchannel that are determined to be busy.
 13. The communication device ofclaim 7, further comprising: one or more wireless transceiversimplemented on the one or more IC devices.
 14. The communication deviceof claim 13, further comprising: one or more antennas coupled to the oneor more wireless transceivers.
 15. A method for wireless communications,comprising: determining, at a client station, that a first communicationchannel is a primary channel of an access point; tuning a wakeup radioof the client station to a second communication channel that correspondsto a wakeup radio (WUR) primary channel of the access point when theaccess point is to transmit WUR beacon frames, wherein the secondcommunication channel is different than the first communication channel;receiving, at the client station, WUR beacon frames via the secondcommunication channel; negotiating with the access point, at the clientstation, a third communication channel via which the client station isto receive wakeup frames for the client station, the third communicationchannel being different than the second communication channel; tuningthe wakeup radio of the client station to the third communicationchannel to receive wakeup frames; receiving, at the client station, afirst wakeup frame via the third communication channel; in response toreceiving the first wakeup frame, transitioning a wireless networkinterface of the client station to an active state; and aftertransitioning the wireless network interface of the client station tothe active state, transmitting, by wireless network interface of theclient station, a packet via the first communication channel.
 16. Acommunication device, comprising: one or more integrated circuit (IC)devices; a wireless network interface device associated with a clientstation, the wireless network interface device implemented on the one ormore IC devices and being configured to: determine that a firstcommunication channel is a primary channel of an access point, andnegotiate, with the access point, a second communication channel viawhich the client station is to receive wakeup frames for the clientstation; and a wakeup radio coupled to the wireless network interfacedevice, the wakeup radio implemented on the one or more IC devices,wherein the wakeup radio is configured to: tune to a third communicationchannel that corresponds to a wakeup radio (WUR) primary channel of theaccess point when the access point is to transmit WUR beacon frames,wherein the second communication channel is different than the firstcommunication channel, receive WUR beacon frames via the thirdcommunication channel, tune the wakeup radio to the second communicationchannel to receive wakeup frames, receive a first wakeup frame via thesecond communication channel, and in response to receiving the firstwakeup frame, prompt the wireless network interface to transition to anactive state; and wherein the wireless network interface device isconfigured to, after transitioning to the active state, transmit apacket via the first communication channel.
 17. The communication deviceof claim 16, further comprising: one or more wireless transceiversimplemented on the one or more IC devices.
 18. The communication deviceof claim 17, further comprising: one or more antennas coupled to the oneor more wireless transceivers.